(+)-2-Hydroxy-3-pinanone ((+)-HyPN, (+)-2a) and (-)-3-hydroxy-2-caranone ((-)-2b) were respectively converted to the corresponding Schiff bases 18a and 18b with 1-(2-thiazolyl)methyiamine (17). Alkylation followed by removal of the chiral auxiliaries (+)-2a and (-)-2b afforded (S)-dolaphenine (10) as an optically pure form. The method was applied to the asymmetric synthesis of the dolaphenine analogs 27a-d.
(+)-2-羟基-3-子戊酮 ((+)-Hy
PN, (+)-2a) 和 (-)-3-羟基-2-
赤霉酸 ((-)-2b) 分别与 1-(2-
噻唑基)
甲胺 (17) 反应,生成相应的席夫碱 18a 和 18b。随后进行烷基化,去除手性助剂 (+)-2a 和 (-)-2b,得到光学纯的 (S)-多拉
苯胺 (10)。该方法被应用于多拉苯
胺类似物 27a-d 的不对称合成。